Metadata Encoding and Transmission Standard

METS is considered as container format to import, store and exchange digital objects within the ViRR:_Virtueller_Raum_Reichsrecht.

METS introduction

"The METS schema is a standard for encoding descriptive, administrative, and structural metadata regarding objects within a digital library, expressed using the XML schema language of the World Wide Web Consortium. The standard is maintained in the Network Development and MARC Standards Office of the Library of Congress, and is being developed as an initiative of the Digital Library Federation."

One METS file corresponds to one digital object (i.e. one digitized work) with all its components and inner structure. Each of the section (descriptive metadata, administrative metadata, structural metadata and files) either reference external information or directly embeds it.

METS is highly flexible and allows multiple representations of the same digital object. In particular, METS does not restrict the usage of metadata schemas (it only defines a set of supported schemas = "extension schemas") and the file inventory can be organized in multiple ways. Therefore, the standard itself does not provide interoperability. METS profiles may reduce this problem to a certain extend.

METS structure

An example METS xml is available from the Fedora homepage and a METS structure diagram is provided as well

Header (metsHdr)

Information about the METS document itself, e.g. various time stamps and the institutions and/or individuals (agent) involved in creating the package:

<METS:metsHdr ID="BOOK1" CREATEDATE="2007-05-20T06:32:00" LASTMODDATE="2007-05-22T06:32:00" RECORDSTATUS="A">
  <METS:agent>ROLE="CREATOR" TYPE="ORGANIZATION">
    <METS:name>Max Planck Institute for History of European Law</METS:name>
  </METS:agent> 
</METS:metsHdr>

Descriptive Metadata (dmdSec)

One or several bibliographic records describing the work - in any metadata format. Descriptive metadata might be embedded in the METS object (mdWrap) or stored externally and pointed to (mdRef).

<METS:dmdSec ID="dmd001">
  <mdRef LOCTYPE="URL" MIMETYPE="application/xml" MDTYPE="OTHER" 
  LABEL="MAB record"></mdRef>
</METS:dmdSec>
<METS:dmdSec ID="dmd002">
  <mdWrap MIMETYPE="application/mab" MDTYPE="OTHER" LABEL="MAB Record">
    <binData>0471nM2.01010024      h001 66230�002 19941207000000.0�003 20070608000000.0�030 zz5d||rz||||7�050 ||||||||||||||�051 n||||||�077 �c0�100 Oertel, Christian Gottfried�331 VollstÉandiges corpus gravaminum evangelicorum�359 An das Licht gestellet von Christian Gottfried Oertel�410aRegensburg�412aNeubauer�501 Erschienen: 1 (1771) - [8] (1775). -Bd. [8] im Verl. Montag, Regensburg, erschienen�710 Corpus Evangelicorum / Gravamen�902   |Corpus Evangelicorum�902   |Gravamen�� 
    </binData>
  </mdWrap>
</METS:dmdSec>
<METS:dmdSec ID="dmd003">
  <mdWrap MIMETYPE="text/xml" MDTYPE="DC" LABEL="Dublin Core Metadata">
    <xmlData>
      <dc:title>Vollständiges corpus gravaminum evangelicorum�</dc:title>
      <dc:creator>Oertel, Christian Gottfried</dc:creator>
      <dc:date>1 (1771) - [8] (1775)</dc:date>
      <dc:publisher>Montag, Regensburg</dc:publisher>
      <dc:type>text</dc:type>
    </xmlData>
  </mdWrap>
</METS:dmdSec>

Administrative Metadata (amdSec)

A collection of administrative metadata available for a METS document and/or its components. This can be:

1. technical metadata (techMD): information regarding the file, e.g. compression, bit depth, etc.
2. IPR metadata (rightsMD): copyright and/or license statement
3. source metadata (sourceMD): "descriptive and administrative metadata regarding the analog source from which a digital library object derives".
4. digital provenance metadata (digiprovMD): "information regarding source/destination relationships between files".

Again, the information can be embedded (mdWrap) or just pointed to (mdRef).

<METS:amdSec>
  <METS:techMD ID="TMD1">
    <METS:mdWrap MDTYPE="OTHER" MIMETYPE="text/xml" OTHERMDTYPE="TECHMD">
      <METS:xmlData>
        <techmd:compression NAME="LZW"/>
        <techmd:image>
          <techmd:bitDepth>24</techmd:bitDepth>
          <techmd:storage PLANARCONFIGURATION="UNKNOWN" SEGMENT="STRIP"/>
          [...]
        </techmd:image>
      </METS:xmlData>
    </METS:mdWrap>
  </METS:techMD>
  <METS:rightsMD ID="RMD1">
    <METS:mdWrap MDTYPE="OTHER" MIMETYPE="text/xml" OTHERMDTYPE="RIGHTSMD">
      <METS:xmlData>
        <rightsmd:versionStatement>Copyright by MPIeR</rightsmd:versionStatement>
      </METS:xmlData>
    </METS:mdWrap>
  </METS:rightsMD>
</METS:amdSec>

File List (fileSec)

The file list is the inventory of all files the object consists of. The list arrange all files into groups (fileGrp), which can be arranged hierarchically.

The actual content may be referenced (xlink:href) or contained within the METS document

<METS:fileSec>
  <METS:fileGrp ID="DATASTREAMS">
    <METS:fileGrp ID="DS1" STATUS="A">
      <METS:file ID="DS1.0" CREATED="2002-05-20T06:32:00" MIMETYPE="image/x-mrsid-image" 
      ADMID="TMD1 RMD1" OWNERID="E" STATUS="A">
        <METS:FLocat LOCTYPE="URL" xlink:href="http://iris.lib.virginia.edu/mrsid/mrsid_images/iva/archerd01.sid" 
        xlink:title="Exhibit Intro: Architectural Drawings, Pavilion III, University of Virginia"/>
      </METS:file>
    </METS:fileGrp>
  </METS:fileGrp>
</METS:fileSec>

Structural Map (structMap)

A representation of the complete object modeled as tree structure. Every node in the tree can be assigned with descriptive as well as administrative metadata

<METS:structMap ID="S1" TYPE="fedora:dsBindingMap">
  <METS:div TYPE="demo:9" LABEL="DS Binding Map for MrSID Image mechanism">
    <METS:div TYPE="MRSID" LABEL="Binding to MrSID file from which different image resolutions will be derived" ORDER="0">
      <METS:fptr FILEID="DS1"/>
    </METS:div>
  </METS:div>
</METS:structMap>

Structural Link (structLink)

"The Structural Links section of METS allows METS creators to record the existence of hyperlinks between nodes in the hierarchy outlined in the Structural Map. This is of particular value in using METS to archive Websites."

Note: Probably not required within the ViRR context

Tools for METS generation

An overview of METS tools is available on the METS homepage

• 7Train - "an XSLT 2.0 tool for generating METS files from XML input. It builds the basic METS structure so that the user can worry about what is specific to the user's project. Includes examples for generating METS from OAI and CONTENTdm records."

• METS Java Toolkit - "for the procedural construction, validation, and marshalling and unmarshalling for METS"

METS profiles

"METS Profiles are intended to describe a class of METS documents in sufficient detail to provide both document authors and programmers the guidance they require to create and process METS documents conforming with a particular profile."

METS profiles define the use of extension schema, rules of description and specify the technical characteristics. METS profiles allow implementers to reduce the flexibility to those constraints they would like to support.

References

Further METS examples

• http://daitss.fcla.edu/wiki/DescriptorTwo
• http://www.fulbrightacademy.org/page/71949/?lp_v=go&lp_u=http$3A$2F$2Fwww.loc.gov$2Frr$2Fmopic$2Favprot$2Fmetsmenu2.html - a very nice overview on the METS primary schema and extension schemas proposed for one project

Metadata Encoding and Transmission Standard

Extensible Markup Language

MAchine-Readable Cataloging

Flexible Extensible Digital Object Repository Architecture

Identifier

Uniform Resource Locator

Maschinelles Austauschformat für Bibliotheken

Dublin Core

Max-Planck-Institut für europäische Rechtsgeschichte

Directory Service

Virtueller Raum Reichsrecht

Extensible Stylesheet Language Transformations

Open Archives Initiative